Pediatric_Swallowing_and_Feeding_Assessment_and_Management,_Third.pdf

Pediatric
Swallowing and Feeding
Assessment and Management
Third Edition

Pediatric
Swallowing and Feeding
Assessment and Management
Third Edition
Joan C. Arvedson, PhD
Linda Brodsky, MD
Maureen A. Lefton-Greif, PhD

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Library of Congress Cataloging-in-Publication Data
Names: Arvedson, Joan C., author, editor. | Brodsky, Linda, editor. |
Lefton-Greif, Maureen A., author, editor.
Title: Pediatric swallowing and feeding : assessment and management / Joan C.
Arvedson, Linda Brodsky, Maureen A. Lefton-Greif.
Description: Third edition. | San Diego, CA : Plural Publishing, [2020] |
Includes bibliographical references and index.
Identifiers: LCCN 2019013064| ISBN 9781944883515 (alk. paper) | ISBN
1944883517 (alk. paper)
Subjects: | MESH: Feeding and Eating Disorders of Childhood | Deglutition
Disorders | Feeding Behavior—physiology | Deglutition—physiology |
Infant | Child
Classification: LCC RJ463.I54 | NLM WM 175 | DDC 618.92/31—dc23
LC record available at https://lccn.loc.gov/2019013064
Disclaimer: Please note that ancillary content (such as documents, audio, and video,
etc.) may not be included as published in the original print version of this book.

v
Contents
Foreword vii
Preface ix
About the Editors xi
Contributors xiii
1 Overview of Diagnosis and Treatment 1
Joan C. Arvedson and Maureen A. Lefton-Greif
2 Anatomy, Embryology, Physiology, and Normal Development 11
3 Neurodevelopmental Assessment of Swallowing and Feeding 75
Brian Rogers and Shannon M. Theis
4 The Upper Airway and Swallowing 149
Robert Chun and Margaret L. Skinner
5 Pediatric Gastroenterology 191
Ellen L. Blank
6 Pediatric Nutrition 237
Mary Beth Feuling and Praveen S. Goday
7 Clinical Swallowing and Feeding Assessment 261
Joan C. Arvedson, Maureen A. Lefton-Greif, and Donna J. Reigstad
8 Instrumental Evaluation of Swallowing 331
Maureen A. Lefton-Greif, Joan C. Arvedson, Robert Chun, and
David C. Gregg
9 Management of Swallowing and Feeding Disorders 369
Joan C. Arvedson, Maureen A. Lefton-Greif, and Donna J. Reigstad
10 Pulmonary Manifestations and Management Considerations 453
for Aspiration
J. Michael Collaco and Sharon A. McGrath-Morrow

vi Pediatric Swallowing and Feeding: Assessment and Management
11 Drooling and Saliva/Secretion Management 479
12 Clinical Genetics: Evaluation and Management of Patients With 517
Craniofacial Anomalies Associated With Feeding Disorders
Julie E. Hoover-Fong and Natalie M. Beck
13 Behavioral Feeding Disorders: Etiologies, Manifestations, and 551
Management
Meghan A. Wall and Alan H. Silverman
Index 577

vii
Foreword
It has been 25 years since the first edition
of this landmark publication Pediatric
Swallowing and Feeding: Assessment and
Management was published. The second,
updated edition was published in 2002.
Now, in 2020, we have the third edition
of this fundamental text concerning the
understanding and care of pediatric swal-
lowing and feeding. The editors, one of
whom unfortunately was deceased before
publication, have recognized the advances
and changes in the understanding of the
information now available for the care of
pediatric swallowing and feeding chal-
lenges. They have recruited an outstanding
group of contributors for this newest edition
and there are numerous critically important
updates and additions. The editors have
included the World Health Organization’s
International Classification of Functioning,
Disability, and Health as the functional
basis for all areas of the book. This text is
important as there are an increased num-
ber of children with complex medical and
health care conditions who are at risk for
feeding and swallowing disorders. This
third edition stresses the need for a team
approach and it also documents the use of
“virtual” teams. This is evidenced through
the chapter contributors who are profes-
sionals in their respective fields. Chapter 10
is especially important now as it documents
the pulmonary manifestations and consid-
erations concerning aspiration in pediatric
patients. Chapter 12 addresses the genetics
underlying many of these conditions, which
was information that was unavailable in the
first two editions.
Pediatric Swallowing and Feeding: Assess-
ment and Management, Third Edition is the
fundamental holistic source for all health
care professionals who provide care for chil-
dren with swallowing and feeding problems
throughout the world. The previous editions
have been, and now this updated third edi-
tion continues to be the standard for infor-
mation concerning diagnosis and care of
these children.
Robert J. Ruben, MD, FAAP, FACS
Distinguished University Professor
Departments of Otorhinolaryngology—
Head and Neck Surgery and Pediatrics
Albert Einstein College of Medicine
Montefiore Medical Center
Bronx, New York

ix
Preface
This third edition of Pediatric Swallowing
and Feeding: Assessment and Management,
now co-edited with Maureen A. Lefton-
Greif, PhD, is published at a time when
recognition of the complexities of infants
and children with swallowing and feeding
disorders is increasing. Recent advances
in genetics and epigenetics and the neuro-
physiologic underpinnings of feeding and
swallowing development and their disor-
ders have contributed to the appreciation of
the complicated inter-relationships among
structures, functions, and the environment
throughout childhood. This body of infor-
mation has advanced this field since publi-
cation of the first two editions of this book
in 1993 and 2002. Consequently, this third
edition is long overdue. It includes signifi-
cant updates and considerable new infor-
mation, making it a “new” edition rather
than a simply revised edition.
We trust that this edition meets the
challenges of balancing updates with new
information, while adhering to the salient
and immutable basic concepts that underlie
this area of practice. Notably, breathing and
eating are basic to survival. Their disrup-
tions can lead to significant compromises
in nutrition and growth, respiratory health,
development and academic skills, and
overall general health and well-being. With
medical advances and the increases in the
survival and life expectancy of medically
fragile children, more attention has been
given to the multidisciplinary needs of these
children. Nonetheless, high-quality evi-
dence to support the care of these children
and the development of consensus-driven
guidelines have not kept pace with the rec-
ognition of the needs of these children.
The World Health Organization’s empha-
sis on “function” and “participation” serve
as essential steps in the development of
meaningful evaluations and effective inter-
ventions, and mandates that professionals
set high priorities on interactions between
caregivers and children, and the need for
non-stressful feedings from preterm infants
through teenage years and into adulthood.
Focusing on only “oral skills” or “safe swal-
lowing” is not enough.
This edition builds on the first two in
which Dr. Linda Brodsky contributed her
extraordinary medical knowledge and lead-
ership in many ways. She is missed not only
for her role in this book, but for her con-
tributions to research and patient care in
pediatric otolaryngology. We have built on
her knowledge and passion for children and
their families.
We acknowledge the many people who
made this edition possible. First, we offer
a special thank you to all the authors who
shared their extensive knowledge and expe-
rience in their specialty areas and for their
generous time commitments given their
busy clinical and research schedules.
We thank Beth Ansel, PhD, and Jeanne
Pinto, MA, for their superb editing, sugges-
tions, and attention to detail. The editors
at Plural Publishing have paid attention
to the many details necessary to bring this
book to publication, and we thank them for
their patience and expertise. We are grateful

x Pediatric Swallowing and Feeding: Assessment and Management
for the families who gave permission for
their children to be photographed adding
examples of the real purposes for all of us—
enhancing the lives of children with swal-
lowing and feeding disorders.
Most of all we thank all the families
and caregivers who have trusted us with
the care of their children. We are in awe of
their courage, inspired by their strength,
grateful for their contributions to the care
of future generations of children with swal-
lowing and feeding disorders, and delight
in the joy they have brought to us. Finally,
we thank our families, to whom this book
is dedicated.

xi
About the Editors
Joan C. Arvedson, PhD, is a speech-language
pathologist, with Specialty in Pediatric Feed-
ing and Swallowing Disorders at the Children’s
Hospital of Wisconsin-Milwaukee and a clini-
cal professor in the Department of Pediatrics,
Medical College of Wisconsin. She is recognized
internationally for her clinical work in pediat-
ric swallowing and feeding disorders, lecturing/
teaching, and scientific publications. The first two
editions of this book were published while she
was at the Children’s Hospital of Buffalo/Kaleida
Health in Buffalo, NY. She and Dr. Lefton-Greif
co-authored Pediatric Videofluoroscopic Swallow
Studies: A Professional Manual with Caregiver
Guidelines. Dr. Arvedson developed an online
course, Interpretation of videofluoroscopic swal-
low studies of infants and children: A study guide
to improve diagnostic skills and treatment planning. She also developed independent study
videoconferences for the American Speech-Language-Hearing Association’s professional
development initiatives. Dr. Arvedson is a founding member of the Board of Certified
Specialists in Swallowing and Swallowing Disorders. She is a Fellow of ASHA and was
awarded Honors of the Association in 2016. Dr. Arvedson is a member of the editorial
board of Dysphagia. She is past-president of the New York State Speech-Language-Hearing
Association and the Society for Ear, Nose, and Throat Advances in Children.

xii Pediatric Swallowing and Feeding: Assessment and Management
Linda Brodsky, MD (1952–2014), an interna-
tionally recognized pediatric otolaryngologist,
was Chief of Pediatric Otolaryngology at the Chil-
dren’s Hospital of Buffalo/Kaleida Health in Buf-
falo, New York; Professor at the State University of
New York at Buffalo Medical School; Director of
the Children Hospital’s Center for Pediatric Oto-
laryngology and Communication Disorders. Dr.
Brodsky was co-editor of the first two editions of
Pediatric Swallowing and Feeding: Assessment and
Management with Dr. Arvedson. In 2014, prelimi-
nary discussions were underway for this third
edition. She’s authored more than 100 scientific
papers and 27 book chapters and served on the
editorial boards of several medical journals. She
was listed in the Best Doctors in America series
and Who’s Who in Science and Engineering. Dr.
Brodsky was presented with the Sylvan Stool award for excellence in teaching by the Society
for Ear, Nose, and Throat Advances in Children. She was a strong advocate for mentorship
of young women in medicine. Her devotion to her patients and tenacity in advocating for
their care was legendary. Dr. Brodsky is missed by her family, colleagues, and patients.
Maureen A. Lefton-Greif, PhD, is Professor in
the Departments of Pediatrics, Otolaryngology—
Head and Neck Surgery, and Physical Medicine
and Rehabilitation at Johns Hopkins Medical
Institutions. She is an internationally recognized
speech-language pathologist for her clinical exper-
tise and research on swallowing and its develop-
ment and disorders in children of all ages. Her
work focuses on optimizing pediatric swallowing
evaluations to facilitate the prompt initiation of
treatment and lessen the consequences associated
with dysphagia. Dr. Lefton-Greif is the recipient
of grants and support from National Institutes of
Health—Deafness and Other Communication
Disorders, Ataxia-Telangiectasia Children’s Proj-
ect, and the Muscular Dystrophy Association. She
and Dr. Arvedson co-authored the book, Pediatric
Videofluoroscopic Swallowing Studies: A Professional Manual with Caregiver Guidelines.
More recently, she and Dr. Bonnie Martin-Harris developed the BaByVFSSImP©. She is a
Fellow of ASHA and a founding member and the first vice-president of the Board of Certified
Specialists in Swallowing and Swallowing Disorders. Dr. Lefton-Greif serves on the editorial
advisory boards of Dysphagia and the Canadian Journal of Speech-Language Pathology.

xiii
Contributors
Joan C. Arvedson, PhD, CCC-SLP, BCS-S
Board Certified Specialist in Swallowing
and Swallowing Disorders
Program Coordinator, Feeding and
Swallowing Services
Children’s Hospital of
Wisconsin-Milwaukee
Milwaukee, Wisconsin
Chapters 1, 2, 7, 8, 9, and 11
Natalie M. Beck, MGC, CGC
Genetic Counselor
Johns Hopkins McKusick-Nathans
Institute of Genetic Medicine
Baltimore, Maryland
Chapter 12
Ellen L. Blank, MD, MA
Retired Pediatric Gastroenterologist
Children’s Hospital of Wisconsin
Associate Adjunct Professor of
Pediatrics-Bioethics
Medical College of Wisconsin
Chapter 5
Robert Chun, MD
Associate Professor
Division of Pediatric Otolaryngology
Department of Otolaryngology
Chapters 4 and 8
J. Michael Collaco, MD, MS, MBA,
MPH, PhD
Associate Professor
Johns Hopkins University School of
Medicine
Eudowood Division of Pediatric
Respiratory Sciences
Baltimore, Maryland
Chapter 10
Mary Beth Feuling, MS, RD, CSP, CD
Advanced Practice Dietitian
Clinical Nutrition
Chapter 6
Praveen S. Goday, MBBS, CNSC, FAAP
Professor of Pediatrics
Division of Pediatric Gastroenterology
and Nutrition
Chapter 6
David C. Gregg, MD
Medical Direction Pediatric Imaging
Associate Professor of Radiology
Chapter 8
Julie E. Hoover-Fong, MD, PhD
Associate Professor
McKusick-Nathans Institute of Genetic
Medicine
Greenberg Center for Skeletal Dysplasias
Johns Hopkins University
Baltimore, Maryland
Chapter 12

xiv Pediatric Swallowing and Feeding: Assessment and Management
Maureen A. Lefton-Greif, PhD,
CCC-SLP, BCS-S
Professor of Pediatrics, Otolaryngology—
Head and Neck Surgery, and Physical
Medicine and Rehabilitation
Eudowood Division of Pediatric
Respiratory Sciences
Medicine
Baltimore, Maryland
Chapters 1, 2, 7, 8, 9, and 11
Sharon A. McGrath-Morrow, MD,
MBA
Division of Pediatric Pulmonary
Johns Hopkins School of Medicine
Baltimore, Maryland
Chapter 10
Donna J. Reigstad, MS, OTR/L
Senior Occupational Therapist
Feeding Disorders Program
Kennedy Krieger Institute
Baltimore, Maryland
Chapters 7 and 9
Brian Rogers, MD
Institute on Development and Disability
Department of Pediatrics
Oregon Health and Science University
Portland, Oregon
Chapter 3
Alan H. Silverman, PhD
Pediatric Psychologist
Chapter 13
Margaret L. Skinner, MD
Assistant Professor, Pediatric
Otolaryngology and Pediatrics
Director, Multidisciplinary Pediatric
Aerodigestive Center
Medicine
Baltimore, Maryland
Chapter 4
Shannon M. Theis, PhD, CCC-SLP
Assistant Professor
Department of Pediatrics
Department of Otolaryngology—Head
and Neck Surgery
School of Medicine
Oregon Health and Science University
Adjunct Faculty, Portland State University
Portland, Oregon
Chapter 3
Meghan A. Wall, PhD, BCBA
Child and Adolescent Psychologist
Assistant Clinical Professor of Psychiatry
Chapter 13

To Linda Brodsky for all she has contributed in the past and how she continues
to influence professionals who follow in her footsteps. We miss you.
To my family: Sons and daughters-in-law Stephen and
Tara, Mark and Julie, along with grandsons Matthew,
Jonathan, and Jason. You are all very special to me.
To my husband Geoffrey, daughters and sons-in-law Jennifer and Daniel,
Alissa and Daniel, and grandchildren Madelyn, Alexander, Emily,
and Cooper. I love you and am grateful to share my life with you.

1
1Overview of Diagnosis
and Treatment
Introduction
During the years since the second edition
of this book, there has been an exponen-
tial increase in basic and clinical research
related to swallowing and feeding in infants
and children. The complexities of interact-
ing systems continue to present challenges
to clinicians and to parents. All involved in
the care of children strive to help them to
be healthy and to grow appropriately, while
ensuring that eating and drinking are plea-
surable with no stress to children or their
caregivers. Factors that have not changed
relate to basic physiologic functions.
Breathing and eating are the most
basic physiologic functions defining the
beginning of life for newborn infants out-
side of the womb. Breathing is reflexive,
life sustaining, and occurs in response to
the transition from the fluid environment
of the womb to the postnatal air environ-
ment. Eating is partly instinctual and partly
a learned response. Eating requires the
ingestion of nutrients provided by an out-
side source. In the newborn infant, sucking
and swallowing require a complex series of
events and coordination of the neurologic,
respiratory, and gastrointestinal (GI) sys-
tems. Normal GI function must occur in
digestion of foods to provide nutrients. All
of these functions are mediated by the integ-
rity of physical and emotional maturation.
The act of feeding is a dyadic process
that requires interaction between the feeder,
usually the mother, and the infant. From
the beginning, feeding should be parent led
with emphasis on quality of feeding, and not
on volume, which often results in stressful
feedings and a potentially reduced volume
of intake and refusals. The pleasure of eating
extends beyond the feeling of satiety to the
pleasure gained through food ingested by
the infant and provided by the mother, who
is most often the primary caregiver. This
interactive primary relationship is the first
for every neonate. It serves as a foundation
for normal development, somatic growth,
communication skills, and psychosocial
well-being. Thus, feeding of the newborn
infant, young child, and rapidly growing
teen is an activity with far-reaching con-
sequences. When feeding is disrupted, the
sequelae can include malnutrition, behav-
ioral abnormalities, and severe distress
for family and child alike. Interruption
of growth and development sometimes
cannot be reversed if it occurs at a critical
time during the early months and years of a
child’s life (Chapter 3). Lifelong disabilities
may result.

2 Pediatric Swallowing and Feeding: Assessment and Management
Prevalence
Currently, more than 100,000 newborn
infants are given diagnoses of feeding prob-
lems after being discharged from acute care
hospitals, and more than one-half mil-
lion children (3–17 years) in the United
States are diagnosed with dysphagia annu-
ally (Bhattacharyya, 2015; CDC/NCHS
National Hospital Discharge Survey, 2010).
The number of children with swallowing
and feeding disorders has been increasing
in part due to recent medical and techno-
logical advances, which have improved the
survival of many infants and children who
previously would not have survived. The
range and complexity of their problems
will continue to challenge the health care,
educational, and habilitation/rehabilitation
systems because many of these children are
now living longer, remaining healthier, and
having greater expectations for leading full
and productive lives.
Approximately 40% of children born
preterm have swallowing/feeding disorders.
Globally, an estimated 15 million infants are
born preterm (less than 37 weeks’ gestation),
and the number is increasing (World Health
Organization [WHO], 2017). Although
many children and their families have ben-
efited greatly, the increasing number of chil-
dren born prematurely at low birth weight
(less than 2,500 g), very low birth weight (less
than 1,500 g), and extremely low birth weight
(less than 600 g) are frequently confronted
with multiple complex medical problems.
In comparison to full-term infants, late
preterm infants (34-0/7 to 36-6/7 weeks
gestation) are at increased risk for respira-
tory and neurologic complications that may
produce or exacerbate feeding difficulties
(Engle, Tomashek, & Wallman, 2007; Mally,
Bailey, & Hendricks-Munoz, 2010). Other
infants with genetic, cardiac, and gastroin-
testinal abnormalities are faced with com-
plex medical and in some instances surgical
problems. Early recognition and interven-
tion have been invaluable despite the cog-
nitive disabilities, cerebral palsy, chronic
pulmonary problems, structural deficits,
and neurologic impairments that infants
endure. Swallowing and feeding problems
compound most of these conditions.
Developmental
Considerations
After the establishment of adequate respi-
ration and physiologic stability, the highest
priority for caregivers is to meet the nutri-
tional needs of their newborn infants. To
achieve this goal successfully, infants and
children of all ages require a well-func-
tioning oral sensorimotor and swallow-
ing mechanism, overall adequate health
(including respiratory, gastrointestinal, and
neurologic), appropriate nutrition, central
nervous system integration, and adequate
musculoskeletal tone.
In addition, the emergence of commu-
nication, an often-overlooked process, is
closely aligned with successful swallowing
and feeding, particularly in young children
(Malas, Trudeau, Chagnon, & McFarland,
2015). Normal feeding patterns are reflected
in the early developmental pathways that
sequentially and rapidly emerge during the
first several months and years of life. Com-
munication is one of the most important
of those pathways. The interrelationship
between feeding, shared by all biologic crea-
tures, and language-based, verbal commu-
nication, unique to humans, cannot be over-
emphasized. The comparative anatomy of
the upper aerodigestive tract and its impli-

1. OVERVIEW OF Diagnosis and Treatment 3
cation for the development of human com-
munication has been established (e.g., Lait-
man & Reidenberg, 1993, 2013; LaMantia et
al., 2016; Lieberman, McCarthy, Hiiemae, &
Palmer 2001; Madriples & Laitman, 1987).
Children who are born prematurely with
very low birth weight or neurologic im-
pairment are commonly found to have swal-
lowing and feeding problems. Other high-
risk children are those experiencing birth
trauma, prenatal and perinatal asphyxia,
and a multitude of genetic syndromes with
accompanying structural and neurologic
impairment (Chapters 3 and 12). The pres-
ence of cardiac, pulmonary, and GI disease
often creates additional difficulty in sorting
out primary and secondary etiologies. Diag-
nosis and management in these patients
present even greater challenges (Table 1–1).
The ability to feed an infant successfully
and thereby nurture an infant is imprinted
early on the maternal–infant relationship.
Normal oral sensorimotor development in-
cludes the establishment of (a) stability and
mobility of the ingestive system, (b) rhyth-
micity, (c) sensation, and (d) oral-motor
efficiency and economy (Gisel, Birnbaum,
& Schwartz, 1998). Optimally, maternal, as
well as paternal, and infant bonding begins
at the outset by providing nutrition with
Table 1–1. Major Diagnostic Categories Associated With Swallowing and Feeding
Disorders in Infants and Children
Neurologic Encephalopathies (e.g., cerebral palsy, perinatal asphyxia)
Traumatic brain injury
Neoplasms
Intellectual disability
Developmental delay
Anatomic and
structural
Congenital (e.g., tracheoesophageal fistula and esophageal
atresia, cleft palate)
Acquired (e.g., tracheostomy, vocal fold paralysis or paresis)
Genetic Chromosomal (e.g., Down syndrome)
Syndromic (e.g., Pierre Robin sequence, Treacher Collins
syndrome, CHARGE syndrome)
Inborn errors of metabolism
Secondary to
systemic illness
Respiratory (e.g., bronchopulmonary dysplasia, chronic lung
disease of prematurity, bronchopulmonary dysplasia)
Gastrointestinal (e.g., inflammatory conditions, GI
dysmotility, constipation)
Congenital cardiac anomalies
Psychosocial
and behavioral
Oral deprivation
Secondary to unresolved or resolved medical condition
Iatrogenic

visual and auditory stimulation of loving
and concerned parents. Thus, swallowing
and feeding disorders likely have negative
impact not only on the physical but also on
the psychosocial well-being of the infant
and child with caregivers.
Sensorimotor Function
The epidemiology of oral sensorimotor dys-
function in the general population and in
the population of children with neurologic
impairments is not well defined. Precise
incidence and prevalence data are difficult
to ascertain. Cerebral palsy (CP) serves
as an example of the range of estimates
that continue to be similar from multiple
sources that have reported approximately
20% to 85% of children with CP are believed
to have swallowing difficulties at some time
during their lives (Benfer, Weir, Bell, Ware,
Davies, & Boyd, 2013; Parkes, Hill, Platt, &
Donnelly, 2010). During the first year of life
of all children with CP, 57% are estimated to
have problems with sucking, 38% with swal-
lowing, and 33% with malnutrition (Reilly,
Skuse, & Poblete, 1996). As the severity of
CP increases, not surprisingly the sever-
ity of the oral sensorimotor dysfunction
increases. The most severely affected are
children with spastic quadriparesis, 90% of
whom have swallowing and feeding prob-
lems (Benfer et al., 2013; Paulson & Vargus-
Adams, 2017; Stallings, Charney, Davies, &
Cronk, 1993). During the first five years
of life, the overall incidence of dysphagia
decreases in children with CP and par-
ticularly in those with better baseline and
improving gross motor function (Benfer,
Weir, Bell, Ware, Davies, & Boyd, 2017 ).
These findings suggest that gross motor
skills and their improvement may herald
those at risk for “persistent” dysphagia.
Team Approaches
to Swallowing/
Feeding Disorders
Feeding disorders that may or may not
include swallowing deficits (dysphagia)
manifest in many different ways. Resistance
to accepting foods, lack of energy for the
work of oral feeding, and oral sensorimotor
disabilities broadly encompass most prob-
lems (Gisel et al., 1998; Kerzner, Milano,
MacLean, Berall, Stuart, & Chatoor, 2015).
Effective management of these medically
complex children depends on the expertise
of many specialists working independently
and as a team (Chapter 9). A few examples
follow, not intended to be an inclusive list,
since different institutions and professionals
within those institutions, carry out patient
care in multiple ways. Some teams may spe-
cialize in specific underlying etiologies or
presentations, for example, Aerodigestive
Clinic, Foregut Clinic (focused specifically
on children with tracheoesophageal fistula
and esophageal atresia (TEF/EA), Tracheos-
tomy/Ventilator Clinic, Craniofacial Team
with a subspecialty clinic for those children
with feeding disorders. Team approaches
also may differ depending on availability of
resources that may even include “virtual”
teams. It is important that teams can offer
coordinated consultation and problem-
solving for co-occurring etiologies and
interrelated problems. Essential compo-
nents can be incorporated in all types of
teams (Table 1–2). The family’s ability to
synthesize and cope with multiple, some-
times disparate opinions must also be a top
priority. Whenever possible, an interdis-
ciplinary team model is encouraged. This
approach refers to interaction of a group of
professionals who meet in person with fam-
ily allowing for optimal efficient communi-
cation. Regardless of the type of team, each

professional brings expertise that is useful in
the solution of complex medical problems.
A group philosophy for both evaluation and
treatment engenders respect for other team
members’ expertise. An organized structure
with a clearly defined leader is important.
Finally, a shared fund of knowledge is criti-
cal and results in creative problem-solving
and fruitful research. In situations where
interdisciplinary teams are not possible,
professionals are urged to develop strate-
gies that promote effective communication
with parents and other primary caregivers.
Team member roles are similar regardless of
the specific type team, with all profession-
als providing services within their scope of
practice and training. Most importantly,
parents/caregivers are integral members of
any team.
Over the past 20 years, there has been
increased recognition of the complex inter-
face between feeding disorders and swal-
lowing impairments in children. The term
feeding disorder refers to inappropriate
development of oral intake and its associ-
ated medical, nutritional, and psychosocial
consequences. Swallowing impairments are
more specific to the process of deglutition.
Hence, all children with swallowing impair-
ments have feeding disorders, but not all
children with feeding disorders have swal-
lowing impairments. Importantly, swallow-
ing impairments can lead to the develop-
ment of feeding disorders. Different types
of models and settings have emerged to
accommodate assessment and treatment of
specific patient populations. Some teams
function primarily in an outpatient setting
and serve as a transitional bridge between
inpatient and outpatient settings. Names for
such teams vary and may include the fol-
lowing: Feeding Clinic; Feeding Disorders
Clinic; Nutrition Clinic; or Swallowing,
Feeding, and Nutrition Clinic; and Feeding
and Growing Clinic. Inpatient swallowing
and feeding teams may be separate from
outpatient teams that have different per-
sonnel. Some teams work across in- and
outpatient settings for assessment and man-
agement of children with specific diagnoses
or presentations. Such teams also vary and
may include craniofacial and aerodiges-
tive teams. The core team members usu-
ally include a physician and other health
care providers as dictated by the needs of
the patient population. The primary oral
sensorimotor swallow therapist is most
likely to be a speech-language pathologist,
although in some instances an occupational
therapist may be primary. All teams benefit
from both when underlying knowledge
and experience is extensive with infants and
children demonstrating swallowing and
feeding disorders.
Table 1–2. Essential Components for Successful Feeding Teams
• Collegial interaction among relevant specialists with active
family involvement
• Shared group philosophy for diagnostic approaches and
treatment protocols
• Team leadership with organization for evaluation and
information sharing
• Willingness to engage in creative problem-solving and research
• Time commitment for the labor-intensive nature of such work

Ethical and Legal Challenges
Underlying Care for
Children With Swallowing/
Feeding Disorders
In addition to making evidence-based deci-
sions, all team members must adhere to
the moral and ethical principles within the
framework of their professions as well as
their scopes of practice (Arvedson & Lefton-
Greif, 2007; Horner, Modayil, Chapman, &
Dinh, 2016). Ethics is a discipline that uses
a systematic approach to examine moral-
ity with the intent of promoting the overall
welfare of the community (Lefton-Greif &
Arvedson, 1997). The four primary princi-
ples of ethical decision-making, respect for
autonomy, beneficence, nonmaleficence,
and justice, are reviewed in detail in Beau-
champ and Childress (1994) and Purtilo
(1988). Adherence to these four commit-
ments is critical to decision making that
goes beyond the realm of facts by rendering
judgements. In addition, for pediatrics, deci-
sion making must take into account in “the
child’s best interests.” Bioethics is the disci-
pline that deals with ethical issues that arise
with advances in medicine. Hence, bioethical
dilemmas are not typically defined by pro-
fessional codes of ethics and are often con-
troversial. Bioethical questions may include
issues that range from allocation of resources
(e.g., expensive drugs used in rare diseases)
to stem cell research. As medical advances
continue, it is likely that all professions
involved with children with dysphagia will
be called on to address bioethical quandaries.
Special Considerations
for School, Home, and
Residential Settings
Oral sensorimotor and swallowing special-
ists frequently function outside of a hospi-
tal setting and outpatient clinic. Assessment
and treatment for children with complex
feeding and other medical problems are
common in a variety of educational (school-
based) and residential (home-based) set-
tings. Working knowledge of the challenges
faced by infants and children with a wide
variety of swallowing problems is manda-
tory. Families may be followed through
a center or home-based educational pro-
gram. These services have been mandated
by federal legislation that guarantees a free
and appropriate educational program for all
handicapped children. The Education for
All Handicapped Children Act (1975–1990)
was revised in 1990 and became known as
Individuals with Disabilities Education Act
(IDEA–Public Law No. 94-142). This law
was established to guarantee that all stu-
dents with disabilities are provided with the
same access to public education as students
without disabilities. “IDEA is composed
of four parts, the main two being part A
and part B. Part A covers the general pro-
visions of the law, Part B covers assistance
for education of all children with disabili-
ties, Part C covers infants and toddlers with
disabilities, which includes children from
birth to age three years, and Part D is the
national support programs administered at
the federal level. Each part of the law has
remained largely the same since the origi-
nal enactment in 1975 Individuals with Dis-
abilities Education Act (2017, November
13).” Section 504 of the Rehabilitation Act
of 1973, as amended (Section 504), clari-
fied information about the Americans with
Disabilities Act (ADA, 2008) in the areas of
public elementary and secondary education
(U.S. Department of Education, 2015). The
ADA (2008) broadened the interpretation
of disability, which clearly includes eating.
Schools are bound by IDEA and 504 because
of their responsibility to provide a free and
appropriate public education (FAPE).

Challenges in Caring for
Feeding Disorders
A comprehensive approach to children with
swallowing and oral sensorimotor func-
tion problems can be hampered by the lack
of a shared fund of knowledge. A clearly
defined set of terms related to this rapidly
expanding field is necessary. Several terms
will be defined here with others defined as
they are encountered throughout the book.
Deglutition1
is the act of swallowing and is
just one process in the broader context of
feeding. Swallowing refers to the entire act
of deglutition from placement of food and
liquid into the mouth until they enter the
upper esophagus. Sucking, chewing, and
swallowing are three physiologically dis-
tinct processes occurring during deglutition
(Kennedy & Kent, 1985). Estimates of the
frequency of swallowing have ranged from
600 to 1,000 times per day (Lear, Flanagan,
& Moorrees, 1965). The highest frequency is
during food intake, and the lowest is during
sleep. Aside from providing nourishment
and hydration, swallowing accomplishes
other purposes, such as the removal of
saliva and mucous secretions from the oral,
nasal, and pharyngeal cavities. A decrease in
swallowing frequency may be coupled with
oral sensorimotor dysfunction and thereby
may result in severe drooling (Chapter 11).
Feeding is a broad term to encompass
the process for getting food/liquid into the
mouth (https://en.oxforddictionaries.com/
definition/deglutition). Once food and liq-
uid enter the mouth, the process continues
with bolus formation as the initial process
to include sucking and chewing (depending
on the composition of the food or liquid)
that leads to moving food/liquid through
the mouth, into the pharynx for initiation of
swallowing. Dysphagia is a swallowing defi-
cit (https://en.oxforddictionaries.com/defi
nition/dysphagia). Oral sensorimotor func-
tion refers to all aspects of sensory and motor
functions involving the structures in the oral
cavity and pharynx related to swallowing
from the lips until the onset (or initiation) of
the pharyngeal phase of the swallow (Chap-
ter 2). Finally, nutrition is the process by
which all living organisms obtain the food
and nourishment necessary to sustain life
andsupportgrowth(https://en.oxforddiction
aries.com/definition/us/nutrition).
Care for children with swallowing and
feeding disorders requires a broad knowl-
edge base that must be supplemented by
a thoughtful and often creative problem-
solving approach. The steps in this approach
are universal to the diagnosis and treatment
of any medical condition or illness. Their
importance to the approach of a medically
complex child cannot be overemphasized.
Team care is most effective in developing
alternate strategies when normal swallow-
ing is absent and nutrition is severely com-
promised (Table 1–3).
1
The terms swallowing and deglutition have been used interchangeably. The term swallowing will be used
throughout the text, unless distinguishing between these terms is relevant to the text.
Table 1–3. Process Steps for Diagnosis
and Treatment of Pediatric Swallowing
and Feeding Disorders
• Define problem feeding and swallowing
• Identify etiology(ies)
• Determine appropriate diagnostic tests
• Plan approach to patient/family
• Teach about problem, implement
treatment
• Monitor progress
• Evaluate progress (outcomes focused)

Clinical and Research
Updates for the Care of
Feeding Disorders
This third edition provides updated clini-
cal and research findings that have direct
impact on care for infants and children with
swallowing and feeding disorders. Empha-
ses continue to be placed on the critical
importance of a fund of knowledge across
multiple systems that are factors in chil-
dren of all ages and all underlying etiolo-
gies. Clinical approaches are presented and
discussed in ways that readers are expected
to find useful in the evaluation and man-
agement of infants and children with oral
sensorimotor dysfunction and swallowing
problems.
The next several chapters cover infor-
mation that provides a basis for understand-
ing the common problems associated with
swallowing and feeding disorders. Knowl-
edge of anatomy, embryology, physiology,
and pathophysiology of the upper aerodi-
gestive tract is fundamental for the under-
standing of infants and children with a wide
range of swallowing and feeding disorders.
The following chapters focus on neurode-
velopment (normal and abnormal), airway,
gastroenterology, and nutrition. These chap-
ters are followed by a chapter on oral sen-
sorimotor clinical feeding evaluation and
a chapter on instrumental assessment with
primary focus on videofluoroscopic swallow
studies and fiberoptic endoscopic examina-
tion of swallowing. Significant clinical and
research advances over the past 10 years are
highlighted in these chapters as well as the
chapter on decision making regarding man-
agement strategies and intervention.
Chapters that follow cover specific top-
ics including aspiration and saliva/secre-
tion management. The chapter on cranio-
facial anomalies has an entirely new section
focused on the genetic basis of conditions
associated with swallowing/feeding prob-
lems in infants and children with craniofa-
cial anomalies. The final chapter focuses on
children with psychologic and behavioral
problems, often accompanied by sensory
factors, as major components in their feed-
ing disorders. The importance of integrat-
ing these factors that include parent/child
relationships cannot be overstated. Func-
tional outcome is the goal for every child
and family.
Clinical case studies that are found at
the end of most chapters provide concrete
examples of teamwork with varied empha-
ses that encompass the depth and breadth
of pediatric feeding disorders. Evaluation
and treatment approaches are included
where supported by clinical experience and
the scientific literature. Medical, psychoso-
cial, and satisfaction outcomes are reported
when available. Although there are some
reports in recent years, the literature con-
tinues to be sparse in the areas of pediatric
swallowing and feeding in normal develop-
ment as well as disorders.
Strong emphasis continues to be placed
on the importance of making a diagno-
sis based on etiology of disease preceding
treatment. All professionals involved in
assessment and management of infants and
children in both medical and educational
settings must have appropriate knowledge
and training to assess and treat infants and
children with dysphagia and related condi-
tions. All decision-making, communications,
and interactions with families and other pro-
fessionals must be carried out with adher-
ence to the respective professional ethical
codes of conduct. The overall importance of
an appropriate fund of knowledge and shared
experience employing team approaches is
emphasized throughout this third edition as
in the earlier editions of this book.

References
Arvedson, J. C., Lefton-Greif, M. A. (2007).
Ethical and legal challenges in feeding and
swallowing intervention for infants and
children. Seminars in Speech and Language,
28(3), 232–238.
Beauchamp, T. L., Childress, J. F. (1994). Prin-
ciples of biomedical ethics. New York, NY:
Oxford University Press.
Benfer, K. A., Weir, K. A., Bell, K. L., Ware,
R. S., Davies, P. S., Boyd, R. N. (2013).
Oropharyngeal dysphagia and gross motor
skills in children with cerebral palsy. Pediat-
rics, 131(5), e1553–1562. doi:10.1542/peds
.2012-3093
Benfer, K. A., Weir, K. A., Bell, K. L., Ware, R. S.,
Davies, P. S. W., Boyd, R. N. (2017). Oro-
pharyngeal dysphagia and cerebral palsy.
Pediatrics, 140. doi:10.1542/peds.2017-0731
Bhattacharyya, N. (2015). The prevalence of
pediatric voice and swallowing problems
in the United States. Laryngoscope, 125(3),
746–750.
CDC/NCHS National Hospital Discharge Sur-
vey, 2010. Retrieved from https://www.cdc
.gov/nchs/data/nhds/8newsborns/2010new8
_numbersick.pdf
Deglutition. (n.d.). In Oxford University Press
dictionary. Retrieved from https://en.oxford
dictionaries.com/definition/deglutition
Dysphagia. (n.d.). In Oxford University Press
dictionary. Retrieved from https://en.oxford
dictionaries.com/definition/dysphagia
Engle, W. A., Tomashek, K. M., Wallman, C.
(2007). “Late-preterm” infants: A popula-
tion at risk. Pediatrics, 120(6), 1390–1401.
doi:10.1542/peds.2007-2952
Gisel, E. G., Birnbaum, R., Schwartz, S. (1998).
Feeding impairments in children: Diagnosis
and effective intervention. International Jour-
nal of Orofacial Myology, 24, 27–33.
Horner, J., Modayil, M., Chapman, L. R., Dinh,
A. (2016). Consent, refusal, and waivers in
patient-centered dysphagia care: Using law,
ethics, and evidence to guide clinical prac-
tice. American Journal of Speech-Language
Pathology, 25, 453–469. doi:10.1044/
2016_
ajslp-15-0041
Individuals with Disabilities Education Act.
(2017, November 13). Retrieved from https://
sites.ed.gov/idea/about-idea/
Kennedy, J. G., Kent, R. D. (1985). Anatomy
and physiology of deglutition and related
functions. Seminars in Speech and Language,
6, 257–273.
Kerzner, B., Milano, K., MacLean, W.C. Jr, Berall,
G., Stuart, S., Chatoor, I. (2015). A practical
approach to classifying and managing feed-
ing difficulties. Pediatrics, 135(2), 344–353.
doi:10.1542/peds.2014-1630.
Laitman, J., Reidenberg, J. (1993). Specializa-
tions of the human upper respiratory and
upper digestive systems as seen through
comparative and developmental anatomy.
Dysphagia, 8, 318–325.
Laitman, J. T., Reidenberg, J. S. (2013). The
evolution and development of human swal-
lowing: the most important function we least
appreciate. Otolaryngology Clinics of North
America, 46(6), 923–935. doi:10.1016/j.otc
.2013.09.005
LaMantia, A. S., Moody, S. A., Maynard, T. M.,
Karpinski, B. A., Zohn, I. E., Mendelowitz,
D., . . . Popratiloff, A. (2016). Hard to swal-
low: Developmental biological insights into
pediatric dysphagia. Developmental Biology,
409(2), 329–342. doi:10.1016/j.ydbio.2015
.09.024
Lear, C. S., Flanagan, J. B., Jr., Moorrees, C. F.
(1965). The frequency of deglutition in man.
Archives of Oral Biology, 10, 83–100.
Lefton-Greif, M. A., Arvedson, J. C. (1997).
Ethical considerations in pediatric dyspha-
gia. Seminars in Speech and Language, 18(1),
79–86.
Lieberman, D. E., McCarthy, R. C., Hiiemae, K.
M., Palmer, J. B. (2001). Ontogeny of post-
natal hyoid and larynx descent in humans.
Archives of Oral Biology, 46(2), 117–128.
Madriples, U., Laitman, J. (1987). Develop-
mental change in the position of the fetal
human larynx. American Journal of Physical
Anthropology, 72, 463–472.
Malas, K., Trudeau, N., Chagnon, M., Mc-
Farland, D. H. (2015). Feeding-swallowing

difficulties in children later diagnosed with
language impairment. Developmental Medi-
cine and Child Neurology, 57(9), 872–879.
doi:10.1111/dmcn.12749
Mally, P. V., Bailey, S., Hendricks-Munoz, K.
D. (2010). Clinical issues in the management
of late preterm infants. Current Problems in
Pediatric and Adolescent Health Care, 40(9),
218–233. doi:10.1016/j.cppeds.2010.07.005
Nutrition. (n.d.). In Oxford University Press dic-
tionary. Retrieved from https://en.oxford
dic
tionaries.com/definition/nutrition
Parkes, J., Hill, N., Platt, M. J., Donnelly, C.
(2010). Oromotor dysfunction and commu-
nication impairments in children with cere-
bral palsy: A register study. Developmental
Medicine and Child Neurology, 52(12), 1113–
1119. doi:10.1111/j.1469-8749.2010.03765.x
Paulson, A., Vargus-Adams, J. (2017). Over-
view of four functional classification systems
commonly used in cerebral palsy. Children
(Basel), 4(4). doi:10.3390/children4040030
Purtilo, R. B. (1988). Ethical issues in teamwork:
The context of rehabilitation. Archives of
Physical Medicine and Rehabilitation, 69(5),
318–322.
Reilly, S., Skuse, D., Poblete, X. (1996). Preva-
lence of feeding problems and oral motor
dysfunction in children with cerebral palsy:
A community survey. Journal of Pediatrics,
129, 877–872.
Stallings,V.A.,Charney,E.,Davies,J.C.,Cronk,
C. E. (1993). Nutritional-related growth failure
of children with quadriplegic cerebral palsy.
Developmental Medicine and Child Neurology,
35, 126–138.
U.S. Department of Education. (2015). Protect-
ing students with disabilities. Retrieved from
https://www2.ed.gov/about/offices/list/ocr/
504faq.html#skipnav2
World Health Organization (WHO). Preterm
birth. Fact sheet. Retrieved from http://www
.who.int/mediacentre/factsheets/fs363/en/
(updated November 2017).

11
2Anatomy, Embryology,
Physiology, and Normal
Development
Summary
The human upper aerodigestive tract is the
most complex neuromuscular unit in the
body. It is the intersection of the digestive,
respiratory, and phonatory systems. Normal
swallowing requires precise integration of
the important functions of breathing, eat-
ing, and speaking. A thorough under-
standing of the anatomy, embryology, and
physiology of these systems is necessary to
appreciate the etiology, diagnosis, and treat-
ment of swallowing and feeding disorders in
infants and children.
Attention to functional anatomy pro-
vides a basis for the discussion of clinically
relevant embryologic development. The
physiology of swallowing, with emphasis on
neurophysiology, posture, and muscle tone,
is presented in detail in this chapter. The
challenges of developmental change begin-
ning with premature infants and extend-
ing through adolescents are nowhere more
apparent than for swallowing and feeding.
Swallowing and feeding are explained in
the context of normal oral sensorimotor
development of the infant and child. Special
focus on the anatomy and physiology of the
airway and gastrointestinal (GI) tract will
help to enhance the reader’s understanding
of the clinical manifestations, diagnosis, and
treatment of swallowing and feeding prob-
lems in children.
Introduction
Deglutition, more commonly referred to as
swallowing,1
is defined as the semiautomatic
motor action of the muscles of the respira-
tory and GI tracts that propels food from the
oral cavity into the stomach (Miller, 1986).
Swallowing functions not only to transport
food to the stomach, but also in clearing the
mouth and pharynx of secretions, mucus,
and regurgitated stomach contents. Thus,
the function of swallowing is nutritive as
well as protective of the lower airways.
The act of swallowing is complex
because respiration, swallowing, and pho-
nation all occur at one anatomic location—
the region of the pharynx and larynx. To
1
The common usage term, swallowing, is used throughout this textbook for ease of reading. Similarly,
ingestion, the taking in of food, will be referred to as feeding or eating (as age appropriate) throughout.

be successful, normal swallowing requires
the coordination of 31 muscles, six cranial
nerves, and multiple levels of the central
nervous system (CNS), including the brain
stem and cerebral cortex (Bosma, 1986).
Thus, understanding the anatomy, embry-
ology, physiology, and normal development
of this functional neuromuscular unit is of
paramount importance to the proper diag-
nosis and treatment of swallowing and feed-
ing disorders in children.
Anatomy
The upper aerodigestive tract consists of
the nose, oral cavity, pharynx, larynx, and
esophagus. The trachea, bronchi, and pul-
monary parenchyma are considered the
lower airways. The upper digestive tract
ends at the entrance to the stomach. Each
area is discussed separately.
Nose
The nose is important for respiration
throughout life, but particularly in neo-
nates (first 28 days of life) and young infants
(up to 6 months), when preferential nasal
breathing is present. The nose also cleans,
warms, and humidifies inspired air. As the
nasal passage continues posteriorly, it opens
at the bilateral posterior nasal choanae into
the nasopharynx, which is an important
anatomic chamber that serves as a resona-
tor for speech production. In addition, the
nasopharynx is one of the two airway con-
duits into the hypopharynx (Figure 2–1).
The lateral nasal walls are composed of
three bones covered with a highly sensitive
INFANT
Tongue
Maxilla
Mandible
Hyoid
Larynx
Trachea
Tongue
Esophagus
Epiglottis
Hypopharynx
Nasopharynx
Vallecula
Soft Palate
Hard Palate
Figure 2–1. Lateral view of the infant’s upper aerodigestive tract. Structures and
boundaries of the oral cavity, pharynx, and larynx are noted.The soft palate is in
close approximation to the valleculae. This anatomic proximity effectively sepa-
rates the oral route for ingestion from the preferred nasal route for respiration.

2. Anatomy, Embryology, Physiology, and Normal Development 13
mucosa—the nasal turbinates. The nose is
separated into two nasal cavities by the mid-
line septum, which is cartilage anteriorly
and bone posteriorly. Septal deviation in
the newborn may occur from birth trauma
and result in severe nasal obstruction lead-
ing to perinatal feeding difficulties (Emami,
Brodsky, Pizzuto, 1996). Other etiologies
of nasal obstruction include, but are not
limited to, choanal atresia, encephalocele,
glioma, nasal dermoid, nasolacrimal duct
cyst, pyriform aperture stenosis, and rhini-
tis (Gnagi Schraff, 2013; see Chapter 4).
Soft palate elevation and retraction seal off
the nasal cavity from the oropharynx and
the oral cavity.
Oral Cavity (Mouth)
The oral cavity is involved in ingestion of
food, vocalization, and oral respiration.
Structures include lips, mandible, maxilla,
floor of the mouth, cheeks, tongue, hard
palate, soft palate, and anterior surfaces of
the anterior tonsillar pillars. Older infants
and children also have teeth for chewing.
The lateral sulci are spaces between the
mandible or maxilla and the cheeks. The
anterior sulci are spaces between the man-
dible or maxilla and the lip muscles.
The structures in the mouth are impor-
tant for bolus formation and oral transit
(described in detail in the following text). In
infancy, the cheeks with fat pads or sucking
pads are important for sucking. The tongue
has attachments to the mandible, hyoid
bone, and styloid process of the cranium by
the extrinsic muscles of the tongue (genio-
glossus, hypoglossus, and styloglossus
muscles) (Bosma, 1972). When anatomic
defects of the lips, palate, maxilla, mandi-
ble, cheeks, or tongue are present, normal
sucking and swallowing may be compro-
mised (see Chapters 4 and 12). In children
with oral sensorimotor problems, food or
liquid can be lodged in both the anterior
and lateral sulci, making bolus preparation
difficult. Muscles involved in bolus forma-
tion and oral transit include the digastric,
palatoglossus, genioglossus, styloglossus,
geniohyoid, mylohyoid, buccinators, and
those muscles intrinsic to the tongue (no
bony attachment, classified by orientation
of the muscle fibers: longitudinal, vertical,
and transverse). Cranial nerves involved
include V, VII, IX, X, XI, and XII (Bosma,
1986; Derkay Schechter, 1998; Perlman
Christensen, 1997).
Pharynx
The pharynx consists of three anatomic
areas (Figures 2–1 and 2–2): the nasophar-
ynx, the oropharynx, and the hypopharynx.
In the infant, the nasopharynx and hypo-
pharynx blend into one structure, and thus
there is no true oropharynx as seen in the
older child. The nasopharynx begins at the
nasal choanae and ends at the elevated soft
palate. The eustachian tubes originate in the
nasopharynx (Bosma, 1967).
As growth and development occur, two
important anatomic changes emerge: (a) the
angle of the nasopharynx at the skull base
becomes more acute and approaches 90°,
and (b) the pharynx elongates so that an
oropharynx is created. The faucial arches
form a bridge between the mouth and the
oropharynx. This junction and the tongue
base form the anterior boundary of the
oropharynx, which extends inferiorly to
the epiglottis. The oropharynx includes
the epiglottis and the valleculae. The val-
leculae are bilateral pockets formed by
the base of the tongue and the epiglottis
(Donner, Bosma, Robertson, 1985). The
hypopharynx (sometimes called the laryn-
geal pharynx) extends from the base of the

epiglottis to the cricopharyngeal muscles in
the upper esophageal sphincter. The ante-
rior wall of the hypopharynx includes the
laryngeal inlet and the cricoid cartilage.
The pyriform sinuses are pockets lateral
and just below the inlet to the larynx. The
vertical enlargement of this space enables
the development of human speech. Phona-
tion of a wide variety of speech sounds can
thus occur. However, this elongation chal-
lenges the timing and coordination needed
for functional swallowing and breathing as
a common and enlarged intersection of the
respiratory and digestive tracts is created
(Laitman Reidenberg, 1993).
The walls of the pharynx consist of three
pairs of constrictor muscles—the superior,
medial, and inferior constrictors. These
striated muscle fibers arise from a median
raphe in the midline of the posterior pha-
ryngeal wall. They extend laterally and
attach to bony and soft tissue structures
located anteriorly. Initiation of the pharyn-
geal swallow function is under voluntary
neural control and becomes involuntary
for completion of the pharyngeal swallow.
This function is under the control of cranial
nerves (CN) V, IX, and X that synapse in the
swallowing center located in the medulla.
Nasopharynx
The nasopharynx is a boxlike structure
located at the base of the skull. It connects
the nasal cavity above with the orophar-
ynx below, and serves as a conduit for air,
OLDER CHILD
Nasopharynx
Oropharynx
Hypopharynx
Larynx
Esophagus
Trachea
Epiglottis
Hyoid
Vallecula
Soft palate Tongue
Figure 2–2. Lateral view of the older child’s upper aerodigestive tract. Note
the wide distance between the soft palate and the larynx. The elongated phar-
ynx is unique to humans and has allowed the development of human speech
production.

a drainage area for the nose and paranasal
sinuses and eustachian tube/middle ear
complex, and a resonator for speech pro-
duction. The boundaries of the nasophar-
ynx are the posterior nasal choanae (anteri-
orly), the soft palate (anterior-inferior), the
skull base (posteriorly), and the hypophar-
ynx in infants and oropharynx in children
and adults (inferiorly). Tongue propulsion
moves a bolus posteriorly and thus assists
in the elevation of the soft palate and closes
off the nasopharynx from the rest of the
pharynx. Anatomic or functional defects of
the soft palate may result in nasopharyngeal
backflow/reflux during oral feedings (Chap-
ters 4 and 12).
The adenoid is a mass of lymphatic tissue
located behind the nasal cavity, in the roof
of the nasopharynx where the nose blends
into the throat. The adenoid, unlike the pala-
tine tonsils, has pseudostratified epithelium.
The adenoid is part of the “Waldeyer ring” of
lymphoid tissue, which includes the palatine
tonsils and the lingual tonsils.
During the first years of life, the adenoid
increases in size. Involution begins at about
age 8 years and extends through puberty.
Excessive enlargement of the adenoid may
cause nasal obstruction and feeding diffi-
culties, even in older children.
Oropharynx
The oropharynx is the posterior extension
of the oral cavity. The oropharynx begins at
the posterior surface of the anterior tonsillar
pillars and extends to the posterior pharyn-
geal wall. The palatine tonsils are attached
to the lateral pharyngeal walls between the
anterior and posterior tonsillar pillars. The
superior boundary of the oropharynx is par-
allel to the pharyngeal aspect of the soft pal-
ate in a line extending back to the posterior
pharyngeal wall. The inferior boundary of
the oropharynx is at the base of the tongue
and includes the epiglottis and valleculae.
The valleculae are wedge-shaped spaces at
the base of the tongue and the epiglottis.
The lingual tonsil is along the tongue base.
When the lingual tonsil becomes enlarged,
it can encroach on the valleculae and cause
significant airway, feeding, and swallow-
ing problems. Enlargement may be seen
when severe gastroesophageal reflux disease
(GERD)/extra-esophageal reflux disease
(EERD)2
is present. The lateral and poste-
rior walls of the oropharynx are formed by
the middle and part of the inferior pharyn-
geal constrictor muscles. The greater cornua
of the hyoid bone are included in the lateral
pharyngeal walls (Donner et al., 1985).
The body of the hyoid bone, located in
the deep musculature of the neck, attaches
to the base of the tongue. The base of the
tongue and the larynx descend inferiorly
during the first 4 years of life. By age 4, the
base of the tongue is anatomically sepa-
rated from the larynx in the vertical plane
and thus becomes the anterior border of the
oropharynx (Caruso Sauerland, 1990).
Because the infant’s larynx is high in the
neck, almost “tucked under” the base of the
tongue, no true oropharynx exists (see Fig-
ures 2–1 and 2–2). Thus, in neonates and
young infants, a single conduit for breath-
ing is created from the nasopharynx to the
hypopharynx that allows them to coordi-
nate sucking, swallowing, and breathing.
2
Gastroesophageal reflux disease (GERD) refers to the abnormal regurgitation of acid into the esophagus
causing symptoms. When acid and other stomach contents emerge from the esophagus into the pharynx,
larynx, mouth, and nasal cavities, the most commonly accepted term is extra-esophageal reflux disease
(EERD) (Sasaki Toohill, 2000).

Hypopharynx
The hypopharynx extends from the base of
the epiglottis at the level of the hyoid bone
down to the cricopharyngeus muscle. Ante-
riorly it ends at the laryngeal inlet above the
true vocal folds at the level of the false vocal
folds and includes the cricoid cartilage. Pos-
teriorly, the hypopharynx ends at the level
of the entrance to the esophagus, which is
guarded by the cricopharyngeus muscle.
This muscle has no median raphe, in con-
trast to the pharyngeal constrictors. Except
during swallowing, belching, or regurgita-
tion, the cricopharyngeus is in a state of
tonic contraction functioning as the pha-
ryngoesophageal sphincter or upper esoph-
ageal sphincter (UES)3
(Caruso Sauer-
land, 1990; Kahrilas et al., 1986). The fibers
of the inferior constrictors attach to the
sides of the thyroid cartilage. These spaces
are known as the pyriform sinuses, and they
extend down to the cricopharyngeus muscle
(Figure 2–3). The oblique fibers of the infe-
rior constrictor muscles end where the hori-
zontal fibers of the cricopharyngeus muscle
3
Terminology is rapidly changing in this field. For purposes of this book, the more familiar term upper
esophageal sphincter (UES) is used.
Figure 2–3. Posterior sketch of the upper aerodigestive tract
(larynx and pharynx). Pathway for food bolus is around the
larynx and down the channels made by the pyriform sinuses,
which elongate during the act of swallowing. The bolus is
moved through the upper esophageal sphincter (UES) par-
tially via action of the hyolaryngeal complex decreasing ten-
sion on the open UES while the larynx is closed and protected
high in the neck under the tongue base.

begin. The lateral and posterior walls of the
hypopharynx are supported by the middle
and inferior constrictors. The anterior
boundary of the hypopharynx is the larynx.
Larynx
The larynx is a complex structure that is the
superior entrance to the trachea. The larynx
consists primarily of cartilages, suspended
by muscle and ligament attachments to the
hyoid bone and cervical vertebrae. The car-
tilages include the epiglottis, thyroid, cri-
coid, and paired arytenoids, cuneiforms,
and corniculates. Intrinsic muscles of the
larynx form the vocal folds (true and false)
that are integral to respiration and pho-
nation. The thyrohyoid and thyrocricoid
ligaments aid in laryngeal suspension and
stability. In order of priority, the three func-
tions of the human larynx are the protection
of the lower airways, respiration, and pho-
nation. The structures important in swal-
low production and in airway protection
during swallowing are described in detail.
Detailed anatomic description of the intrin-
sic muscles of the larynx (involved primar-
ily with phonation) is beyond the scope of
this chapter.
The most important structures of the
larynx that protect against aspiration are
the paired arytenoid cartilages and the two
pairs of vocal folds. In most humans, the
epiglottis plays a role in airway protection.
However, there are examples of children
with congenitally absent epiglottis (Koem-
pel Holinger, 1998) and functional oral
feeding. The epiglottis has a flattened lin-
gual surface, which acts to direct food later-
ally into the recesses formed by the pyriform
sinuses. The movement of food is directed
away from the midline and the laryngeal
inlet. The arytenoid cartilages and the ary-
epiglottic folds, reinforced by the smaller
cuneiform and corniculate cartilages, move
medially to further buttress the larynx from
penetration. The larynx is elevated anteri-
orly under the tongue and mandible by
the hyolaryngeal complex (hyoid bone and
attached musculature).
The valvelike function provided by
the paired false and true vocal folds is the
next and most critical level of laryngeal
structures involved in airway protection.
The false vocal folds (ventricular folds) are
primarily involved in regulating the expira-
tion of air from the lower respiratory tract
(Sasaki Isaacson, 1988). In contrast, the
true vocal folds do not resist expired air but
can prevent inspired air (and foreign mate-
rial) from entering the larynx. Thus, specific
anatomic abnormalities at the laryngeal
level must be precisely defined to avoid seri-
ous sequelae of an incompetent larynx.
Neuroanatomy of the Larynx
Multilevel sphincteric closure of the upper
airway is controlled by the recurrent laryn-
geal nerves. The aryepiglottic folds, made
up of the superior part of the thyroaryte-
noid muscles, approximate to cover the
superior inlet of the larynx. The anterior
gap is protected by the posteriorly displaced
epiglottis, the posterior gap closed by the
arytenoid cartilages (Figure 2–4). The false
vocal folds form the roof of the laryngeal
ventricles and are the second level of protec-
tion within the larynx. The thyroarytenoid
muscles aid in adduction of the false vocal
folds. The third level of protection is the
true vocal folds, with the inferior part of the
thyroarytenoid muscles providing the bulk
of these folds. The true vocal folds attach
to the vocal processes of the arytenoid car-
tilages posteriorly, to the inside surface of
the thyroid lamina laterally, and to the thy-
roid notch anteriorly. Muscular pull by the
arytenoid cartilages controls movement of

the true vocal folds during both swallowing
and phonation.
Innervation of the protective laryn-
geal and respiratory functions is centrally
located in the brain stem. This control relies
on fine sensory and motor innervation to
the region. Sensory innervation of the
supraglottic and glottic areas is provided by
the internal branch of the superior laryngeal
nerve (SLN), a branch of the vagus nerve
(CN X). The recurrent laryngeal nerve
(RLN) (also from CN X) provides sensory
innervation to the subglottic mucosa. The
posterior part of the true vocal folds and the
superior surface of the epiglottis appear to
be the most densely innervated part of the
larynx (Sasaki Isaacson, 1988). Chemi-
cal and thermal receptors are also found in
the supraglottic larynx and are sensitive to
a variety of stimuli. In particular, receptors
sensitive to water in infants and young chil-
dren may explain the favorable response to
cool mist in children with laryngotracheitis,
also known as “croup.” The effect of the mist
slows the rate of respiration while increas-
ing tidal volume, resulting in an overall pos-
itive effect on the respiratory status (Sasaki,
Suzuki, Horiuchi, Kirchner, 1979). Other
sensory receptors of the larynx include joint,
aortic, baroreceptors, and stretch receptors.
These afferent impulses are interpreted at
the brain-stem level in the tractus solitarius.
The ipsilateral RLN (vagus—CN X)
innervates all of the intrinsic muscles of the
larynx except the cricothyroid muscles. The
cricothyroid is innervated by the external
branch of the SLN. Only the interarytenoid
muscles receive bilateral innervation from
the recurrent laryngeal nerves. All of the
intrinsic muscles of the larynx are involved
in adduction except the posterior cricoary-
tenoid muscles, the only abductors of the
vocal folds. Control at the brain-stem level
is within the nucleus ambiguus.
Anatomic changes in the larynx are evi-
dent when SLN paralysis occurs. The lateral
cricoarytenoid muscle, a laryngeal adduc-
tor, rotates the posterior laryngeal commis-
Figure 2–4. Superior view of the larynx showing the intrinsic structures of the larynx.
The laryngeal ventricle is the space between the false and true vocal folds. Airway
closure occurs from distal to proximal regions (i.e., first true vocal folds, next false
vocal folds, and finally aryepiglottic folds).

sure to the paralyzed side. This results in a
foreshortening of the vocal fold on the ipsi-
lateral side, which gives an appearance of
asymmetry or tilt to the larynx. In contrast,
paralysis of the RLN results in a paramedian
position of that vocal fold, caused by the
unopposed adductor action of the ipsilateral
cricothyroid muscle, innervated by an intact
external branch of the SLN.
Esophagus
The esophagus is a muscular tube lined with
mucosa that propels food from the hypo-
pharynx to the stomach. The cricopha-
ryngeus is the major muscle of the upper
esophageal sphincter (UES), also called
the cricopharyngeal sphincter and pharyn-
goesophageal segment (PE segment) and
forms the junction between the hypophar-
ynx and the esophagus. The mucosa just
above the cricopharyngeus muscle is thin
and vulnerable to injury, such as perfora-
tion from foreign bodies (Caruso Sauer-
land, 1990). The gastroesophageal or lower
esophageal sphincter (LES) forms the junc-
tion between the esophagus and the stom-
ach. The LES has transient relaxations in
contrast to the UES which is in tonic con-
traction (discussed later in this chapter).
These sphincters help keep the esophagus
empty between swallows (Derkay Schech-
ter, 1998).
The esophagus is in close proximity to
other structures in the neck and thorax.
In the neck, it lies anterior to the cervical
vertebrae, posterior to the trachea, and
between the carotid arteries. The recurrent
laryngeal nerves are located on either side
of the esophagus in the tracheoesophageal
groove. Other important structures in the
posterior mediastinum related to breathing,
feeding, and swallowing are the left main-
stem bronchus, the aortic arch, the pericar-
dium, and the nerves and blood vessels to
the esophagus.
The wall of the esophagus is composed
of four layers: mucosa, submucosa, mus-
cularis, and adventitia. The mucosa of the
esophagus constitutes three layers of tissue:
epithelium, lamina propria, and muscularis
mucosae. The mucosa of the esophagus is
stratified squamous, continuous with the
epithelium in the pharynx. Intrinsic mus-
cles of the esophagus are found in an outer
longitudinal layer and an inner circular
layer. The posterior and lateral portions of
the longitudinal muscle encircle the inner
muscle layer in a spiral pattern. The upper
third of the esophagus is composed of stri-
ated muscle similar to the constrictors in the
pharynx; the lower two-thirds is made up
of smooth muscle fibers. The pharynx and
proximal esophagus are the only regions in
the body where striated muscle is not under
voluntary neural control. Both sympathetic
and parasympathetic fibers innervate the
esophagus, although the cricopharyngeus
muscle seems to be primarily under para-
sympathetic control via the vagus nerve
(DerkaySchechter,1998).Thevagalmotor
nerve fibers to striated muscles of the upper
esophagus arise from the nucleus ambig-
uus in the brain stem and those to smooth
muscles of originate in the dorsal motor
nucleus, next to the nucleus ambiguus.
This brief description of the esophagus does
not begin to cover the complexities of neu-
ral innervation, muscle types and function,
mucosal changes, connective tissue, and the
extracellular matrix of the esophagus (see
Perlman Konrad Schulze-Delrieu, 1997,
with additional references).
Significantanatomicdifferencesarefound
between the infant and older child/adult (see
Figures 2–1 and 2–2). These differences are
listed by anatomic location in Table 2–1.

Embryology
Embryology is the branch of biology involv-
ing the study of prenatal development that
includes the embryo and the fetus. The anat-
omy of the oral cavity, pharynx, larynx, and
esophagus is the result of embryologic pro-
cesses that begin at fertilization of the ovum
and continue through infancy, childhood,
and even into adulthood. In this section, the
development of the head and neck, respi-
ratory system, digestive system, and perti-
nent parts of the CNS are described in some
detail. However, this section is intended to
provide a brief overview of the develop-
mental processes. Salient features of the
related cardiovascular and musculoskeletal
systems are also reviewed. The interested
student is referred to texts on embryology
for further detail (e.g., Brookes Zietman,
1998; Moore, Persaud, Torchia, 2015;
Table 2–1. Anatomic Locations and Differences Between the Infant’s and Older Child’s
Upper Aerodigestive Tracts
Anatomic
Location
Differences
Infant Older Child
Oral cavity Tongue fills mouth Mouth is larger
Edentulous Dentulous
Tongue rests between lips and sits
against palate
Tongue rests on floor of mouth
Cheeks have sucking pads (fatty
tissue within buccinators)
Tongue rests behind the teeth and is
not against palate
Relatively small mandible Buccinators are muscles for chewing
only
Sulci important in sucking Mandibular-maxillary relationship
relatively normal
Sulci have little functional benefit
Pharynx No definite/distinct oropharynx Elongated pharynx, so distinct
oropharynx exists
Obtuse angle at skull base in
nasopharynx
90º angle at skull base
Larynx One-third adult size Less than one-third true vocal fold of
cartilage
Half true vocal fold of cartilage Flat, wide epiglottis
Narrow, vertical epiglottis By 2 years of age, approximates
adult position re: cervical vertebrae
High in the neck, re: cervical
vertebrae

Schoenwolf, Bleyl, Brauer, Francis-West,
Philippa, 2015). Normal embryologic devel-
opment related to oral sensorimotor func-
tion and swallowing is discussed later in this
chapter, followed by a brief description of
some of the congenital abnormalities that
present with swallowing problems.
Embryonic Period (Weeks 1 to 8)
Human prenatal development begins at fer-
tilization with formation of a zygote. The
zygote is a diploid cell containing 46 chro-
mosomes with half from the mother and
half from the father. Fertilization of the egg
is completed within 24 hours of ovulation.
Repeated mitotic divisions of the zygote
result in a rapid increase in the number of
cells. By the 3rd week, three germ layers
(ectoderm, mesoderm, and endoderm) are
formed from which all tissues and organs
of the embryo develop. The ectoderm gives
rise to the epidermis and the nervous sys-
tem. The mesoderm gives rise to smooth
muscle, connective tissue, and blood vessels.
The endoderm gives rise to the epithelial
linings of respiratory and digestive systems.
During the 3rd week, the CNS and the
cardiovascular system begin to form. The
neural plate, which is the origin of the
CNS, gives rise to the neural folds and the
beginning of the neural tube. The neural
crest consists of neuroectodermal cells that
form a mass between the neural tube and
the overlying surface ectoderm. The neural
crest gives rise to the sensory ganglia of the
cranial and spinal nerves, as well as to sev-
eral skeletal and muscular components in
the head and neck region.
All major organ systems are formed
during the 4th to 8th weeks of development.
During the 4th week, the trilaminar embry-
onic disc forms into a C-shaped cylindrical
embryo, which later becomes the head, tail,
and lateral folds. The dorsal part of the yolk
sac becomes incorporated into the embryo
and gives rise to the primitive gut (Moore et
al., 2015). Infolding at the head region yields
the oropharyngeal membrane. The heart is
carried ventrally, and the developing brain
is at the most cranial part of the embryo. By
the end of the 8th week, the embryo begins
to have a human appearance.
Fetal Period (Week 9 to Birth)
The fetal period begins in the 9th week and
is primarily marked by rapid body growth,
with relatively slower head growth com-
pared with the rest of the body. Differen-
tiation of tissues and organs continues dur-
ing this time. A brief description of major
embryologic changes is followed by more
detailed information regarding systems
directly involved in swallowing.
9 to 12 Weeks
At the beginning of the 9th week, the head
makes up half the length of the fetus, mea-
sured from the crown to the rump (Caruso
Sauerland, 1990). At 9 weeks, the face is
broad, with widely separated eyes, fused
eyelids, and low-set ears. The legs are short
with relatively small thighs. By the end of
12 weeks, the upper limbs will have almost
reached the final relative lengths, although
lower limbs are still slightly shorter than the
final relative lengths.
13 to 16 Weeks
By the 13th week, body length has more
than doubled. Body growth occurs so
rapidly that by the 16th week, the head is
relatively small compared with the end of

the 12th week. Ossification of the skeleton
begins during this period.
17 to 20 Weeks
Somatic growth slows down, but length
continues to increase. Fetal movements are
beginning to be felt by the mother. Eyebrows
and head hair become visible at 20 weeks.
21 to 25 Weeks
Substantial weight gain occurs during this
time. By 24 weeks, the lungs begin produc-
ing surfactant, which is a surface-active
lipid that maintains the patency of the
developing alveoli of the lungs. However,
the respiratory system is still very immature
and unable to sustain life independently. If
born at this premature stage, however, sur-
factant replacement therapy has allowed
some of these premature infants to survive.
26 to 29 Weeks
The lungs are capable of air exchange, but
with some difficulty. The CNS is beginning
to mature, and rhythmic breathing move-
ments are possible although not present in
all infants. Control of body temperature
begins. The eyes are open at the beginning
of this period.
30 to 34 Weeks
By 30 weeks, the pupillary light reflex of
the eyes can be elicited. By 34 weeks, white
fat in the body makes up about 8% of body
weight. The presence of white fat is a devel-
opmental milestone for normal feeding
potential because the infant then begins to
show some nutritional reserves. Body tem-
perature regulation is more stable by 34 to
35 weeks.
35 to 40 Weeks
At 36 weeks, the circumferences of the head
and the abdomen are approximately equal.
After 36 weeks, the abdomen circumfer-
ence may be greater than that of the head.
Although at full term the head is much
smaller relative to the rest of the body than
it was during early fetal life, it is still reason-
ably large in relation to the size of their bod-
ies. The expected time of birth is 38 weeks
after fertilization (gestational age or post-
conceptual age) or 40 weeks after the last
menstrual period. By full term, the amount
of white body fat should be about 16% of
body weight.
Head and Neck Development
Branchial (Pharyngeal)
Apparatus Development
The head and neck are developed from the
branchial apparatus, which consists of bran-
chial arches, pharyngeal pouches, branchial
grooves, and branchial membranes. Bran-
chial arches are derived from the neural
crest cells and begin to develop early in the
4th week, as the neural crest cells migrate
into the future head and neck region. By the
end of the 4th week, four pairs of branchial
arches are visible (Figure 2–5). The fifth
and sixth pairs are too small to be seen
on the surface of the embryo. The bran-
chial arches are separated by the branchial
grooves, which are seen as prominent clefts
in the embryo.
The branchial arches contribute to
formation of the face, neck, nasal cavities,
mouth, larynx, and pharynx, with the mus-
cular components forming striated muscles
in the head and neck. Anatomic develop-
ment of the thyroid and cricoid cartilages

beginning at the 13th week (up to 27 weeks)
reveals a correlation between laryngeal
length and fetal crown-rump (C-R) with no
differences between genders (Gawlikowska-
Stoka et al., 2010). The width of both thy-
roid cartilage laminae was significantly
larger in males than in females across 13 to
27 weeks (Gawlikowska-Stoka et al., 2010)
with similar sexual dysmorphism noted for
glottis opening in postmortem study (Fay-
oux, Marciniak, Deisme, Storme, 2008).
These authors suggest that findings may
be useful in planning treatment of airway
emergencies.
The cranial nerve supply for each bran-
chial arch, along with the skeletal structures
and muscles derived from the branchial
arches are described in Table 2–2.
Facial Development
The mandible is the first structure to form
by the merging of the medial ends of the
two mandibular prominences of the first
branchial arch during the 4th week. Maxil-
lary prominences of the first branchial arch
grow medially toward each other, as do the
medial nasal prominences soon thereaf-
ter. The auricles of the external ear begin
to develop by the end of the 5th week. As
the brain enlarges, a prominent forehead
is noted, the eyes move medially, and the
Heart prominence
Yolk stalk
Body stalk
Otic vesicle
Third branchial arch
Second branchial arch
(Hyoid)
First branchial arch
(Mandibular)
Optic vesicle
Figure 2–5. Human embryo at about 28 days showing early branchial (pharyn-
geal) apparatus relationships. Four pairs of branchial arches can be seen with
their respective branchial grooves.

24
Table 2–2. Cranial Nerves, Structures, and Muscles Derived From Branchial
(Pharyngeal) Arch Components
Arch Cranial Nerves Structures Muscles
First (mandibular) Trigeminal (V) Mandible Muscles of mastication
Maxilla Mylohyoid and anterior
belly of digastric
Malleus, incus Tensor tympani
Zygomatic bone Tensor veli palatini
Temporal bone
(squamous portion)
Second (hyoid) Facial (VII) Stapes Muscles of facial
expression
Styloid process Stapedius
Hyoid bone
(Lesser cornu)
(Upper body)
Stylohyoid
Posterior belly of digastric
Third Glossopharyngeal
(IX)
Hyoid bone
(Greater cornu)
(Inferior body)
Stylopharyngeus
Hypoglossal (XII) Posterior one-third
of tongue
Epiglottis
Fourth and sixth Vagus (X)
SLN
RLN
Tongue
Laryngeal cartilages
Epiglottis (fourth)
Palatoglossus
Cricothyroid
Levator veli palatini
Pharyngeal constrictors
Intrinsic muscles of
larynx
Striated muscles of
esophagus
Note. RLN = recurrent laryngeal nerve; SLN = superior laryngeal nerve.
Source: Adapted from Structures derived from pharyngeal arch components. In K. L. Moore (Ed.), The
developing human (10th ed., p. 160). Philadelphia, PA: Elsevier, 2015.

external ears ascend. At 16 weeks, the eyes
begin to migrate and are situated more ante-
riorly than laterally. The ears are closer to
their final position at the sides of the head.
The medial and lateral nasal promi-
nences are formed by growth of the sur-
rounding mesenchyme, which results in
formation of primitive nasal sacs. The nasal
cavity is separated from the oral cavity by
the oronasal membrane (Figure 2–6), which
ruptures at about 6 weeks. This rupture that
forms the primitive choanae brings the nasal
and oral cavities into direct communication.
If the oronasal membrane does not rupture,
a choanal atresia will make it impossible for
an infant to suck, swallow, and breathe syn-
chronously (Chapter 4). The posterior nasal
choanae are located at the junction of the
nasal cavity and the nasopharynx once the
development of the palate is completed.
Palatal development begins toward the
end of the 5th week and is completed in
the 12th week (Figure 2–7). Development
occurs from anterior to posterior as mes-
enchymal masses merge toward the mid-
line. The primary palate, or medial palatine
process, develops at the end of the 5th week
and is fused by the end of the 6th week to
become the premaxillary part of the max-
illa. The primary palate gives rise to a very
small part of the adult hard palate that is
positioned just posterior (or caudal) to the
incisive foramen of the skull. Subsequently,
the secondary palate develops from two
horizontal lateral palatine processes that
fuse over the course of a few weeks from the
incisive foramen posterior to the soft palate
and uvula. The anterior hard palate (ossi-
fied) is fused by 9 weeks, and the muscular
soft palate is completed by the 12th week.
The nasal septum develops downward
from the merged medial nasal prominences.
During the 9th week, the fusion between the
nasal septum and the palatine processes
begins anteriorly and is completed at the
posterior portion of the soft palate by the
12th week. This process occurs in conjunc-
tion with the fusion of the lateral palatine
processes. The palatine processes fuse about
a week later in female than in male fetuses,
which may explain why isolated cleft palate
is more common in female infants (Burdi,
Mandibular process
Rupturing oronasal membrane
Pharynx
Tongue
Oral cavity
Primary palate
Nasal cavity
Figure 2–6. Sagittal section showing oronasal membrane, which separates
the nasal and oral cavities. At about 6 weeks, the oronasal membrane ruptures
to form the primitive choanae. This brings the nasal and oral cavities into direct
communication.

1969). As the jaws and the neck develop, the
tongue descends and occupies a relatively
smaller space in the oral cavity. The tongue
also develops from the third and fourth
branchial arches.
Prenatal Sucking, Swallowing,
and Breathing Development
The pharyngeal swallow is one of the first
motor responses in the pharynx. It has been
reported between 10 and 14 weeks’ gesta-
tion (Humphry, 1970). Pharyngeal swallows
have been observed in delivered fetuses at
12.5 weeks’ gestation (Humphry, 1970).
Ultrasound studies reveal nonnutritive
suckling/sucking and swallowing in most
fetuses by 15 weeks’ gestation (Moore et
al., 2015). Sucking, suckling, and sucking act
are terms often used interchangeably in the
literature to describe mouthing movements
and ingestion of food by infants (Wolf
Glass, 1992). Suckling, the earliest intake
pattern for liquids, is characterized by a
definite backward and forward movement
of the tongue, with the backward phase
more pronounced (Figure 2–8). In contrast,
sucking begins to emerge at four months of
age, and involves more of an up and down
movement of the tongue and active use of
the lips. A suckling response may be elic-
ited at this stage as noted by the finding that
stroking the lips yields suckling responses
in spontaneously aborted fetuses. True
suckling begins around the 18th to the 24th
week. Self-oral-facial stimulation precedes
suckling and swallowing with consistent
swallowing seen by 22 to 24 weeks’ gesta-
tion (Miller, Sonies, Macedonia, 2003).
Tongue protrusion does not extend beyond
the border of the lips (Morris Klein, 1987).
By the 34th week, most healthy fetuses, if
born at that time, can suckle and swallow
well enough to sustain nutritional needs via
the oral route. Some infants appear coordi-
nated enough to begin oral feedings by 32 to
33 weeks’ gestation (Cagan, 1995).
Infants born late preterm (between 34
0/7 and 36 6/7 weeks of gestation), account
for 70% of all preterm births (Davidoff et al.,
2006; Dong Yu, 2011; Loftin et al., 2010;
Perugu, 2010). The incidence of late pre-
Philtrum
Upper lip
Choanae
Nasal septum
Nostril
Primary palate
(Premaxilla)
Lateral
palatine
process
Figure 2–7. Palatal development from anterior to posterior.The lateral processes fuse
to form most of the hard and soft palate, completed by 9 and 12 weeks, respectively.

term births has increased markedly in the
past two decades with increased prevalence
of medical problems that are also noted in
early term (37 to 38 weeks’ gestation) com-
pared to infants born full term (39 to 41
weeks) (Brown, Speechley, Macnab, Natale,
Campbell, 2014; Hwang et al., 2013; Sahni
Polin, 2013). Feeding difficulties are
reported with high frequency in infants who
are bottle or breastfeeding (Dosani et al.,
2017). There are limited data on feeding
problems in late preterm infants (Bloom-
field et al., 2018; DeMauro, Patel, Medoff-
Cooper, Posencheg, Abbasi, 2011). Gianni
and colleagues (2015) note that nutritional
support is likely to be needed for those late
preterm infants with a birth weight less
than or equal to 2000 g, gestational age of
34 weeks, and born small for gestational age,
develop respiratory distress syndrome, and
require a surgical procedure.
Decreased rates of fetal suckling are
associated with alimentary tract obstruction
or neurologic damage, the latter of which
manifests as intrauterine growth restriction
(Derkay Schechter, 1998). It is estimated
that 450 ml of the total 850 ml of amniotic
fluid produced daily is swallowed in utero
(Bosma, 1986).
Ultrasound has shown that suckling
motions increase in frequency in the later
months of fetal life. The frequency of the
suckling motions can be modified by taste.
Taste buds are evident at 7 weeks’ gestation,
with distinctively mature receptors noted at
12 weeks (Miller, 1982). Ultrasonography is
shown to have a high degree of intra- and
interobserver repeatability for analysis of
sucking and swallowing movements (Levy
et al., 2005).
Digestive System Development
The endoderm of the primitive gut, which
forms in the 4th week, gives rise to most of
the epithelium and glands of the digestive
tract. The muscles, connective tissue, and
other layers comprising the wall of the diges-
tive tract are derived from the splanchnic
mesenchyme (loosely organized connective
tissue) surrounding the endodermal primi-
tive gut. The foregut, midgut, and hindgut
make up the primitive gut.
The derivatives of the foregut include
the pharynx and its derivatives, respira-
tory system, esophagus, stomach, duode-
num (up to the opening of the bile duct),
Figure 2–8. Suckling and sucking comparisons of tongue and mandibular
action. Suckling is characterized by in–out tongue movements and some jaw
opening and closing; sucking is characterized by up–down tongue movements
and less vertical jaw action. Readers are reminded that terms may be used dif-
ferently in the literature.

liver, pancreas, and the biliary apparatus
(gallbladder and biliary duct system). The
celiac artery supplies all derivatives except
the pharynx, respiratory tract, and most of
the esophagus.
The esophagus elongates rapidly and
reaches its final relative length by the 7th
week. If it does not elongate sufficiently,
part of the stomach may be displaced supe-
riorly through the esophageal hiatus in the
thorax, resulting in a congenital hiatal her-
nia (Moore et al., 2015). (See Chapter 5.)
Although the upper third of the esophagus
is made up of striated muscle and the lower
two thirds of smooth or nonstriated muscle,
there is a transition region between the cer-
vical and thoracic levels where striated and
smooth muscle fibers intermingle. Both
types of muscle are innervated by branches
of the vagus nerve (CN X). The esophagus
and airways share common innervations
with complex interrelationships of afferents
and efferents having both sympathetic and
parasympathetic responses, as reviewed by
Jadcherla (2017).
Respiratory System
Development
The respiratory system begins to develop
during the 4th week by formation of a
median laryngotracheal groove in the cau-
dal end of the ventral wall of the primi-
tive pharynx. This laryngotracheal groove
develops into a laryngotracheal diverticu-
lum that then becomes separated from
the primitive pharynx (cranial part of the
foregut) by longitudinal tracheoesophageal
folds. During the 4th and 5th weeks, these
folds fuse and form the tracheoesophageal
septum, which is a partition dividing the
foregut into a ventral and a dorsal portion.
The ventral portion is the laryngotracheal
tube that eventually becomes the larynx,
trachea, bronchi, and lungs. The dorsal
portion becomes the esophagus. It is clear
from these early embryologic changes that
the airway and digestive systems are inextri-
cably related because they initially develop
from the same embryonic structure.
Laryngeal Development
The opening of the laryngotracheal tube
into the pharynx becomes the primitive
glottis. The laryngeal cartilages and muscles
are derived from the 4th and 6th pairs of
branchial arches (see Table 2–2). The epithe-
lium of the mucous membrane lining of the
larynx develops from the endoderm of the
cranial end of the laryngotracheal tube. The
mesenchyme proliferates rapidly at the cra-
nial end of the laryngotracheal tube to pro-
duce paired arytenoid swellings at 5 weeks
(Figure 2–9A). The primitive glottis (Fig-
ure 2–9B), a slitlike opening, is converted
into a T-shaped opening as the arytenoid
swellings grow toward the tongue (Figure
2–9C). This action reduces the developing
laryngeal lumen again to a narrow slit. The
laryngeal lumen is temporarily occluded by
rapid proliferation of the laryngeal epithe-
lium. By the 10th week, recanalization of
the larynx occurs (Figure 2–9D). The epi-
glottis develops from the caudal part of the
hypobranchial eminence. This eminence is
produced by proliferation of mesenchyme
in the ventral parts of the third and fourth
branchial arches.
Tracheobronchial and
Pulmonary Development
The laryngotracheal tube distal to the lar-
ynx gives rise to the epithelium and glands

of the trachea and lungs. The tracheal car-
tilages, connective tissue, and muscles are
derived from the surrounding splanchnic
mesenchyme. The cartilage is in the form
of C-shaped rings in the trachea and major
bronchi. In more peripheral airways, the
cartilage becomes more irregular and less
prominent. The subglottic space is defined
by the cricoid cartilage, the only cartilage
that forms a complete ring. The respira-
tory system develops so that it is capable of
immediate function by full-term gestation.
The lungs must have sufficiently thin alve-
olocapillary membranes and an adequate
amount of surfactant for normal respira-
tion to occur.
Maturation of the lungs occurs in four
periods (Moore et al., 2015):
n Pseudoglandular period (6 to 16 weeks):
Resembles an exocrine gland and
by 16 weeks all major elements have
formed, except those involved with gas
exchange. Respiration is not possible.
n Canalicular period (16 to 26 weeks):
Overlaps with previous period since
cranial segments mature faster than
caudal segments. Lung tissue becomes
highly vascular by the end of this
period. Fetuses born near the end
of this period may survive if given
intensive care, but survival is not always
A B
C D
5 Weeks 6 Weeks
7 Weeks 10 Weeks
Arytenoid
swelling
Arytenoid
swelling
Epiglottis
Primitive glottis
Glottis
Cartilages
Glottis
Epiglottis Epiglottis
Epiglottis
Figure 2–9. Embryologic stages of laryngeal development. A. At 5 weeks, paired arytenoid
swellings develop at cranial end of the laryngotracheal tube. B. At 6 weeks, the primitive glottis
can be seen. C. At 7 weeks, T-shaped opening is evident in the glottis as arytenoid swellings
grow toward the tongue. D. At 10 weeks, recanalization of the larynx occurs.

possible due to respiratory and other
systems still being relatively immature.
n Terminal saccular period (26 weeks to
birth): Many terminal saccules develop,
and their epithelium becomes very
thin. Capillaries bulge into developing
alveoli. The blood–air barrier is
established through intimate contact
between epithelial and endothelial cells
that permit adequate gas exchange
for survival. Complex development of
type I and II alveolar cells takes place.
The type II cells secrete pulmonary
surfactant, which is a monomolecular
film, over the internal walls of the
terminal saccules. That action lowers
surface tension at the air–alveolar inter-
face. Production of surfactant increases
during the final stages of pregnancy,
especially during the last two weeks.
n Alveolar period (32 weeks to 8 years):
Exactly when this period begins
depends on the definition of the
term alveolus. At 32 weeks, saccules
are present and analogous to alveoli.
However, characteristic mature alveoli
do not form until after birth with about
95% of alveoli developing postnatally.
During the first few months after birth,
an exponential increase is seen in the
surface of the air–blood barrier that
is accomplished by multiplication of
alveoli and capillaries. The lungs of
full-term newborn infants contain
about 50 million alveoli (one sixth of
adult number), which make their lungs
denser than adult lungs. By 2 years of
age, most postnatal alveolar develop-
ment is completed (Thurlbeck, 1982).
The lungs are about half-filled with
fluid at birth. Aeration of the lungs
occurs from the rapid replacement of
intra-alveolar fluid by air. The fluid is
cleared by three routes: (a) through
mouth and nose by pressure on the
fetal thorax during delivery, (b) into
the pulmonary capillaries, and (c) into
the lymphatics and pulmonary arteries
and veins. Normal lung development
depends on three factors: (a) adequate
thoracic space for lung growth, (b) fetal
breathing movements, and (c) adequate
amniotic fluid volume (Moore et al.,
2015).
Cardiovascular System
Development
The cardiovascular system is the first organ
system to function in the embryo. By the
end of the 3rd week, blood begins to circu-
late, and the first heartbeat occurs at 21 to
22 days. The heart develops from splanch-
nic mesenchyme as paired endocardial
heart tubes form and fuse into a single heart
tube, which is the primitive heart. From the
4th to the 7th week, the four chambers of
the heart are formed. The critical period of
heart development is from Day 20 to Day
50 after fertilization. The partitioning of the
primitive heart results from complex pro-
cesses, and defects of the cardiac septa are
relatively common.
Fetal blood is oxygenated in the pla-
centa. The lungs are nonfunctional as
organs of respiration during prenatal life.
Adequate respiration in the newborn infant
is dependent on normal circulatory changes
occurring at birth. The modifications that
establish postnatal circulatory patterns at
birth are gradual and continue for the first
several months of life.
Congenital heart disease (CHD) is the
most common cause of major congenital
anomalies, occurring in an estimated 8 per
1,000 live births (van der Linde et al., 2011).
Detection of fetal CHDs is possible as early
as the 17th or 18th week of development.
Although the underlying causes of CHD

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